---
id: migration-v4
title: Migration Guide to v4.x
sidebar_label: Migration to v4.x
description: Guide for migrating to react-native-reanimated-carousel v4.x
keywords:
  - react-native-reanimated-carousel
  - reanimated-carousel
  - reanimated carousel
  - react-native
  - snap-carousel
  - react native
  - snap carousel
  - ios
  - android
  - carousel
  - snap
  - reanimated
image: 
slug: /migration-v4
---

# Migration Guide to v4.x

This guide will help you migrate your application from react-native-reanimated-carousel v3.x to v4.x.

## Version Requirements

Before upgrading, ensure your project meets these version requirements:

```json
{
  "react": ">=18.0.0",
  "react-native": ">=0.70.3",
  "react-native-gesture-handler": ">=2.9.0",
  "react-native-reanimated": ">=3.0.0"
}
```

## Breaking Changes

### 1. Gesture Handler Configuration

The `panGestureHandlerProps` has been replaced with `onConfigurePanGesture`:

```tsx
// Before (v3.x)
<Carousel
  panGestureHandlerProps={{
    activeOffsetX: [-10, 10],
  }}
/>

// After (v4.x)
<Carousel
  onConfigurePanGesture={(gesture) => {
    'worklet';
    gesture.activeOffsetX([-10, 10]);
  }}
/>
```

### 2. Event Name Changes

- `onScrollBegin` has been renamed to `onScrollStart`

```tsx
// Before (v3.x)
<Carousel onScrollBegin={() => console.log('Started scrolling')} />

// After (v4.x)
<Carousel onScrollStart={() => console.log('Started scrolling')} />
```

### 3. Animation API Updates

The `customAnimation` function now receives the item index as a second parameter:

```tsx
// Before (v3.x)
<Carousel
  customAnimation={(value) => ({
    opacity: value
  })}
/>

// After (v4.x)
<Carousel
  customAnimation={(value, index) => ({
    opacity: value,
    transform: [{ 
      scale: index % 2 ? 1 : 1.1 
    }]
  })}
/>
```

### 4. Event Handler Worklets

All gesture callbacks now run as worklets by default:

```tsx
// Before (v3.x)
<Carousel
  onGestureStart={runOnJS(() => {
    console.log('Gesture started');
  })}
/>

// After (v4.x)
<Carousel
  onGestureStart={() => {
    'worklet';
    console.log('Gesture started');
  }}
/>
```

## New Features

### 1. Container Styling

A dedicated `containerStyle` prop has been added for styling the carousel container:

```tsx
<Carousel
  containerStyle={{
    backgroundColor: 'white',
    borderRadius: 8,
  }}
/>
```

### 2. Minimum Scroll Distance

New `minScrollDistancePerSwipe` prop to prevent unintended item switches:

```tsx
<Carousel
  minScrollDistancePerSwipe={15}
/>
```

### 3. Fixed Direction Scrolling

Control scroll direction with the new `fixedDirection` prop:

```tsx
<Carousel
  fixedDirection="positive"  // or "negative"
/>
```

### 4. Progress Change Handling

The `onProgressChange` now supports direct SharedValue updates:

```tsx
// Before (v3.x)
const progress = useSharedValue(0);
<Carousel
  onProgressChange={(offsetProgress, absoluteProgress) => {
    progress.value = absoluteProgress;
  }}
/>

// After (v4.x)
const progress = useSharedValue(0);
<Carousel
  onProgressChange={progress}
/>
```

### 5. Enhanced Pagination Components

New Pagination components with improved customization:

```tsx
// Basic Pagination
<Pagination.Basic
  progress={progress}
  data={data}
  dotStyle={{ backgroundColor: "#262626" }}
  activeDotStyle={{ backgroundColor: "#f1f1f1" }}
/>

// Custom Pagination with Animation
<Pagination.Custom
  progress={progress}
  data={data}
  customReanimatedStyle={(progress, index) => {
    'worklet';
    return {
      transform: [{
        scale: interpolate(progress.value, 
          [index - 1, index, index + 1], 
          [0.8, 1, 0.8]
        )
      }]
    }
  }}
/>
```

### 6. Improved Web Support

Better handling of window size changes in browser environments and enhanced web compatibility.

## Technical Improvements

- Improved performance with reduced rendering work
- Better handling of pointer events in ItemLayout component
- Fixed parallax layout compatibility with the new architecture
- Enhanced type definitions and exported TAnimationStyle type
- Fixed issues with spring animations and gesture handling
- Improved behavior for non-controlled components

## Breaking Changes in Behavior

### Default Index Handling

The `defaultIndex` prop behavior has changed:

```tsx
// Before (v3.x) - defaultIndex changes would reset the carousel
<Carousel defaultIndex={index} />

// After (v4.x) - subsequent defaultIndex changes are ignored
// Use programmatic control if you need to change the index after mount
<Carousel 
  defaultIndex={index} // Only initial value is considered
  ref={carouselRef}
/>

// To change index programmatically, use the ref:
// carouselRef.current?.scrollTo({ index: newIndex, animated: true })
// See: /programmatic-control for detailed examples
```

## Migration Steps

1. **Update Dependencies**
   - Ensure all peer dependencies meet the minimum version requirements
   - Update react-native-reanimated-carousel to version 4.x

2. **Update Gesture Handling**
   - Replace all instances of `panGestureHandlerProps` with `onConfigurePanGesture`
   - Update gesture configurations to use the new worklet-based API

3. **Update Event Handlers**
   - Rename `onScrollBegin` to `onScrollStart`
   - Update any code relying on these event callbacks

4. **Review Animation Code**
   - Update custom animations to handle the new index parameter if needed
   - Test all custom animations with the new API

5. **Optional Enhancements**
   - Consider using the new `containerStyle` prop for better styling control
   - Implement `minScrollDistancePerSwipe` if needed
   - Evaluate if `fixedDirection` would improve your carousel behavior

6. **Migrate Pagination**
   - If using custom pagination, migrate to the new Pagination components
   - Verify behavior with defaultIndex if using it

7. **Verify Web Compatibility**
   - Test in browser environments to ensure smooth web compatibility
   - Update type definitions if needed
   - Test pointer event handling in custom implementations

## Example Migration

Here's a complete example showing the migration of a typical carousel implementation:

```tsx
// Before (v3.x)
<Carousel
  loop
  width={width}
  height={height}
  data={data}
  onScrollBegin={() => console.log('scroll started')}
  panGestureHandlerProps={{
    activeOffsetX: [-10, 10]
  }}
  enableSnap={true}
  customAnimation={(value) => ({
    opacity: value
  })}
/>

// After (v4.x)
<Carousel
  loop
  width={width}
  height={height}
  data={data}
  onScrollStart={() => console.log('scroll started')}
  onConfigurePanGesture={(gesture) => {
    'worklet';
    gesture.activeOffsetX([-10, 10]);
  }}
  snapEnabled={true}
  customAnimation={(value, index) => ({
    opacity: value
  })}
  containerStyle={{
    borderRadius: 8
  }}
/>
```